Finding the Fourth Proportional to 1,087.30, 1,500.70 and 688.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.30 : 1,500.70 = 688.72 : x
2. Step 2: Convert to fraction form
   1,087.30/1,500.70 = 688.72/x
3. Step 3: Cross multiply
   1,087.30x = 1,500.70 × 688.72
4. Step 4: Simplify right side
   1,087.30x = 1,033,562.10
5. Step 5: Solve for x
   x = 1,033,562.10/1,087.30
6. Step 6: Final answer
   x = 950.58